What's coming after silicon?

I have a question for Wendell: 
Since Moore's law is reaching its physical limits, and chip makers are concentrating on power consumption, what do you think will be the next big thing that will improve processing capabilities? I've heard all this fuss about quantum computers (that I don't really understand, please master Wendell explain them :P) and graphene, So yeah, what du think?

General mistake; power consumption isn't the only thing manufacturers are thinking about.

 

Improving ISAs SIMD and cache are the main thing they are improving.

 

 

 

I could be wrong but i don't think its the silicon that's holding us back on computing but the copper we use. 

Graphene will probably come before quantum computers since research into mass production of graphene is getting more attention than quantum computers right now. Graphene conducts much less heat than silicon and conducts electricity better as well. Quantum computers are basing around having atoms in superposition (look it up if you don't know what that is). A set of two atoms in superposition is a qubit (sorta like a processor core) but scientists are unable to get more than a few qubits to run in sync. So the idea of a personal quantum computer is far in the future. Graphene? I can't wait.

Turing machine:

  • A Turing machine is a model used to simulate the logic of algorithms.
  • A Turing machine at its most basic level consists of a memory capacity and a read/write component.
  • The memory capacity is often represented as an infinite piece of tape which is divided into squares. The squares can contain a 1 or 0 or nothing.
  • The read/write component can create and erase the value in each square and move up and down the tape to access other squares.
  • The read/write component forms instructions to create algorithms and thus a Turing machine forms the basis of a computer system.

Quantum Turing Machine:

  • The squares in a classical Turing machine can be 1 or 0 or nothing. Each calculation can only be performed one at a time.
  • The squares in a quantum Turing machine can be 1 or 0 or nothing or 1 and 0 at the same time (superposition).
  • Therefore, simultaneous calculations can be performed at one time in a quantum Turing machine.
Quantum computers:
  • 1s and 0s are called bits, but a quantum computer operates on the superposed state of a bit as well. Thus, a quantum bit or qubit is utilised in quantum computer.
  • Qubits in a physical sense could be electrons, photons, ions or even atoms.
  • The read/write component of the Turing machine would need the capability to manipulate these atomic or sub-atomic particles to make them into qubits.

Entanglement:

  • When you or an instrument observes a qubit, it will be a 1 or 0. The superposed state is never observed. This phenomenon turns a quantum computer back into a regular computer.
  • To overcome this, the measurements must be made indirectly to conserve the system's integrity.
  • One potential mechanism to exploit qubits is the quantum mechanical phenonmenon called entanglement.
  • Entanglement forces two particles to share the same properties; the particles becoming "entangled".
  • The properties of one particles will be the inverse of the properties of the other particle.
  • So if a particle is in a superposed state (for example, spinning up and spinning down), when the particle is observed, it will choose spin up or spin down, but an entangled particle will be the opposite.
  • This allows the states of the particles to be known without directly observed one of the entangled particles.

So entanglement seems to be the best candidate for a quantum computer at the moment. If qubits can be exploited properly, a quantum computer would be millions of times faster than the most powerful computer today. A 64-qubit quantum computer would possess more than 20 teraflops of processing power I think.

The limitation comes strictly from size.

You can only make a transistor so small before it stops functioning. 

Here's a video.

www.youtube.com/watch?v=rtI5wRyHpTg

 

Yeah, graphene based stuff is likely the next step consumer wise.  It's getting easier to produce and manipulate everyday.